If I specify a System property multiple times when invoking JVM which value is used?
java, jvm, system-properties
Solution
The java.util.System class is backed by a Properties class, which is just an extension of Hashtable. Assuming the values are read in order when passing as arguments to the JVM, then the last value assigned will be the final value.
Problem
If I specify a system property multiple times when invoking the JVM which value will I actually get when I retrieve the property? e.g. ``` java -Dprop=A -Dprop=B -jar my.jar ``` What will be the result when I call `System.getProperty("prop");`? The Java documentation on this does not really tell me anything useful on this front. In my non-scientific testing on a couple of machines running different JVMs it seems like the last value is the one returned (which is actually the behavior I need) but I wondered if this behavior is actually defined officially anywhere or can it vary between JVMs?